Fuel cell stack control system, control method

Abstract

A fuel cell stack control system and method, the method includes the steps of: acquiring a temperature of the stack in real time by detection by a temperature sensor, determining whether the stack real time temperature is greater than a first predetermined temperature, and performing a next step if the stack real time temperature is not greater than the first predetermined temperature; acquiring a current of the stack in real time, determining whether a real time current outputted by the stack is greater than a first predetermined current, and performing step 3 if the real time current outputted by the stack is not greater than the first predetermined current; acquiring a voltage of the stack in real time, determining whether a real time voltage outputted by the stack is less than the first predetermined voltage, and adjusting a temperature control assembly to maintain a rotation speed of an initial duty ratio if the real time voltage outputted by the stack is not less than the first predetermined voltage.

Description

Cross-reference to Related Applications ,

[0001] This application claims priority to a Chinese patent application with an application date of March 31, 2022 and an application number of 202210337877.4, and all the contents of this application are incorporated herein by reference.

Technical Field

[0002] This application relates to the technical field of hydrogen fuel cells, for example, to a fuel cell stack control system and a control method.

Background Art

[0003] A fuel cell is a device that directly converts the chemical energy of a fuel into electrical energy. In theory, if the fuel is continuously supplied, the fuel cell can continuously generate electricity and is praised as the fourth generation of power generation technology following hydropower, thermal power, and nuclear power. Fuel cells have advantages such as high fuel energy conversion efficiency, low noise, and no emissions, and can be widely used in means of transportation such as automobiles, buses, trucks, drones, motorcycles, and backup power supplies, fixed power plants, etc.

[0004] A fuel cell stack releases a large amount of heat in the operating state, and if the generated heat is not discharged in a timely manner, the temperature of the stack will gradually increase. However, a fuel cell requires an appropriate temperature during use to achieve the optimal performance of the system. If the stack temperature is too low, the catalytic activity will decrease, the output voltage will be low, and the stack performance will deteriorate. But if the stack temperature is too high, the moisture in the proton exchange membrane is likely to volatilize, causing a decrease in the humidity of the proton exchange membrane. When it is too dry, it will cause damage to the proton exchange membrane, reduce the conduction efficiency of the proton exchange membrane for hydrogen ions, and further affect the performance of the fuel cell stack. Therefore, a reasonable temperature is very important, and a cooling system is required to reasonably control the temperature during the operation of the fuel cell.

[0005] In related technologies, the fault diagnosis and handling methods for fuel cell stacks generally require shutting down the system, starting a fan to cool it down, and then performing an operational shutdown procedure on the fuel cell stack to eliminate the fault when the stack temperature exceeds a predetermined value. This is time-consuming and cumbersome, and fails to meet the requirement of continuous stack operation. [Overview of the Initiative]

[0006] This invention provides a fuel cell stack control system and control method that solves the problem in related technologies where, when the stack temperature exceeds a predetermined value, it is necessary to shut down the system, start a fan to cool it, and perform an operation stop process on the fuel cell stack to eliminate the fault, which is time-consuming and cumbersome, and does not satisfy the requirement to keep the stack running continuously.

[0007] One embodiment of the present invention proposes a fuel cell stack control system and control method, and includes the following four aspects.

[0008] In the first embodiment, the present application provides a stack temperature control method. Step 1 involves obtaining the temperature of the stack in real time by detection using a temperature sensor, determining whether the real-time stack temperature is greater than a first predetermined temperature, adjusting the rotation speed of the temperature control assembly to maintain the stack temperature below the first predetermined temperature if the real-time stack temperature is greater than the first predetermined temperature, and executing Step 2 if the real-time stack temperature is not greater than the first predetermined temperature. Step 2 involves acquiring the current from the stack in real time, determining whether the real-time current output by the stack is greater than a first predetermined current, and if the real-time current output by the stack is greater than the first predetermined current, linearly adjusting the rotation speed of the temperature control assembly to a predetermined duty cycle or less according to the magnitude of the current, and if the real-time current output by the stack is not greater than the first predetermined current, then executing step 3. Step 3 includes acquiring a voltage to the stack in real time, determining whether the real-time voltage output by the stack is less than a first predetermined voltage, and if the real-time voltage output by the stack is less than the first predetermined voltage, opening the exhaust valve to exhaust air and blowing for a predetermined time while maintaining the rotational speed of the temperature control assembly at a predetermined duty cycle, and if the real-time voltage output by the stack is not less than the first predetermined voltage, adjusting the temperature control assembly to maintain the rotational speed at the initial duty cycle.

[0009] In one embodiment, step 1 is performed as follows: If the stack real-time temperature is greater than a first predetermined temperature, the further step is to determine whether the temperature detection sensor is functioning correctly. The further step includes, if the temperature sensor is functioning correctly, adjusting the rotational speed of the temperature control assembly with a PID, and if the temperature sensor is not functioning correctly, causing the temperature control assembly to maintain its current rotational speed and performing step 3.

[0010] In one embodiment, step 2 is performed as follows: The steps include determining whether the real-time temperature of the stack is greater than a second predetermined temperature when the real-time current output by the stack is greater than a first predetermined current, If the stack real-time temperature is greater than the second predetermined temperature, the rotational speed of the temperature control assembly is linearly adjusted to a predetermined duty cycle or less according to the magnitude of the current; if the stack real-time temperature is not greater than the second predetermined temperature, the temperature control assembly is made to maintain its current rotational speed, and step 3 is performed. The procedure further includes: adjusting the temperature control assembly to a specific rotational speed at the predetermined duty cycle, determining whether the stack real-time temperature is greater than a first predetermined temperature, returning to step 1 if the stack real-time temperature is greater than the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, causing the temperature control assembly to maintain the current rotational speed and performing step 3.

[0011] In one embodiment, step 3 is: The steps include opening the exhaust valve to release the exhaust, blowing the temperature control assembly for a predetermined time while maintaining its rotational speed at a predetermined duty cycle, and then determining whether the real-time voltage output by the stack is less than a first predetermined voltage. The further steps include: adjusting the exhaust policy to shorten the exhaust interval if the real-time voltage output by the stack is less than a first predetermined voltage; and adjusting the temperature control assembly to maintain the rotational speed at the initial duty cycle if the real-time voltage output by the stack is not less than a first predetermined voltage.

[0012] In one embodiment, step 3 is: After opening the exhaust valve to exhaust air and blowing the temperature control assembly for a predetermined time while maintaining the rotational speed at a predetermined duty cycle, if the real-time voltage output by the stack is still less than the first predetermined voltage, The steps include acquiring the real-time voltage of a single cell and determining whether the voltage of each single cell is within a second predetermined voltage range, The steps include: adjusting the exhaust policy of the temperature control assembly and reducing the exhaust interval of the exhaust valve until the stack operates normally, with the rotational speed of the temperature control assembly maintained at the initial duty cycle when the voltage of each single cell is within a second predetermined voltage range; and until the stack also operates normally, with the temperature control assembly maintaining the rotational speed at the initial duty cycle when the voltage of each single cell is outside the second predetermined voltage range.

[0013] In one embodiment, the period for acquiring the temperature of the stack in real time by detection by the temperature sensor is 0.5 to 2 minutes.

[0014] In one embodiment, the temperature control assembly includes a heat dissipation fan provided to cool the fuel cell stack.

[0015] In a second embodiment, the present invention further provides a fuel cell stack control system comprising at least one data acquisition unit and at least one control unit, wherein the data acquisition unit comprises a temperature detection unit electrically connected to the control unit and feeding back the real-time temperature of the stack to the control unit, a current detection unit electrically connected to the control unit and feeding back the real-time current of the stack to the control unit, and a voltage detection unit electrically connected to the control unit and feeding back the real-time voltage of the stack to the control unit, wherein the control unit adjusts the rotational speed of a temperature control assembly based on the data analysis results by analyzing the real-time data from the data acquisition unit by comparing it with a first predetermined temperature, a first predetermined current, and a first predetermined voltage.

[0016] In one embodiment, a pressure sensor is provided to detect the pressure range of hydrogen gas introduced into the stack, and to protect the stack by closing the intake valve of the stack when the pressure range is higher or lower than a predetermined value, A temperature sensor is provided to detect the temperature inside the stack, and if the temperature inside the stack is higher or lower than a predetermined value, it will turn off the stack to protect it. An intake valve is installed in the hydrogen supply pipeline of the stack to control the amount of hydrogen gas supplied to the stack and the frequency of discharge. A control system further comprising an exhaust valve installed at the exhaust port of the stack, which controls the amount of exhaust gas discharged and the frequency of discharge after the reaction in the stack.

[0017] In one embodiment, the control unit is A first decision module that determines whether the stack real-time temperature is greater than a first predetermined temperature, wherein if the stack real-time temperature is greater than the first predetermined temperature, the first decision module adjusts the rotation speed of the temperature control assembly to maintain the stack temperature below the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, the first decision module executes a second decision module. A second decision module that determines whether the real-time current output by the stack is greater than a first predetermined current, wherein if the real-time current output by the stack is greater than the first predetermined current, the second decision module linearly adjusts the rotation speed of the temperature control assembly to a predetermined duty cycle or less according to the magnitude of the current, and if the real-time current output by the stack is not greater than the first predetermined current, the second decision module executes the third decision module. A third decision module that determines whether the real-time voltage output by the stack is less than a first predetermined voltage, wherein if the real-time voltage output by the stack is less than the first predetermined voltage, the third decision module opens the exhaust valve to exhaust air and blows the temperature control assembly for a predetermined time while maintaining the rotational speed of the temperature control assembly at a predetermined duty cycle, and if the real-time voltage output by the stack is not less than the first predetermined voltage, the third decision module adjusts the temperature control assembly to maintain the rotational speed at the initial duty cycle.

[0018] In one embodiment, the control unit includes a first voltage detection mechanism provided to detect the output voltage of the entire stack, and a plurality of second voltage detection mechanisms provided to detect the real-time voltage of each of the plurality of single cells, the first voltage detection mechanism and the second voltage detection mechanisms are electrically connected to the control unit, and the real-time voltage of the stack and the single cell voltage are fed back to the control unit.

[0019] This invention relates to a fuel cell stack control system and control method, and compared to related technologies, it has the following beneficial effects. 1. By timely determining changes in stack temperature, output current, and output voltage, this application achieves a cooling effect by adjusting the rotation speed of the temperature control assembly without affecting the normal operation of the stack, ensuring that the fuel cell stack is always used within an optimal temperature range. 2. According to the temperature control method of the fuel cell stack in this application, when the stack exceeds a predetermined value, there is no need to shut down and then start the temperature control assembly for cooling, nor is it necessary to perform a stop operation on the fuel cell stack to eliminate faults, and it can continue to operate normally.

Brief Description of the Drawings

[0020] [Figure 1] It is a flowchart of the stack temperature control method in Embodiment 1 of this application. [Figure 2] It is a fuel cell stack control system in Embodiment 2 of this application.

Modes for Carrying Out the Invention

[0021] (Embodiment 1) As shown in FIG. 1, FIG. 1 is a flowchart of the stack temperature control method in Embodiment 1 of this application, and the stack temperature control method includes the following steps 1, step 2, and step 3.

[0022] Step 1: Obtain the temperature of the stack in real time by detection with a temperature sensor, determine whether the stack real-time temperature is greater than a first predetermined temperature. If the stack real-time temperature is greater than the first predetermined temperature, adjust the rotation speed of the temperature control assembly to keep the stack temperature lower than the first predetermined temperature. If the stack real-time temperature is not greater than the first predetermined temperature, execute step 2.

[0023] Specifically, real-time temperature acquisition of the stack is realized by a temperature sensor attached to the stack. If the battery stack temperature is too high, it directly affects the performance and lifespan of the fuel cell. Therefore, the processing unit cools the fuel cell stack by adjusting the rotation speed of the temperature control assembly when the received feedback temperature exceeds a preset first predetermined temperature. Since the first predetermined temperature is generally lower than the temperature at which shutdown protection is triggered, direct shutdown due to excessively high stack temperature is avoided. According to the above method, the rotation speed of the temperature control assembly can be adjusted earlier just before the stack heats up to improve heat dissipation efficiency and ensure that the fuel cell stack remains in the optimal temperature range. In this embodiment, since the stack is cooled by air cooling, the temperature control assembly is equipped with a heat dissipation fan for cooling the fuel cell stack.

[0024] In this embodiment, the first predetermined temperature may be 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, or 50°C, but is not limited to these values. Since the aforementioned first predetermined temperature is generally lower than the temperature at which shutdown protection is triggered, it is necessary to detect temperature changes in the stack in a timely manner. This requires high detection accuracy and sensitivity from the temperature sensor, and if the temperature sensor makes a mistake, it is likely to cause a rapid increase in the temperature of the entire stack, affecting the normal operation of the stack. Accordingly, step 1 further includes the steps of determining whether the temperature sensing sensor is functioning correctly if the stack real-time temperature is greater than a first predetermined temperature, adjusting the rotational speed of the temperature control assembly with a PID if the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is not greater than a first predetermined temperature, causing the temperature control assembly to maintain its current rotational speed and performing step 3.

[0025] Here, the PID adjustment described above corrects the rotational speed of the temperature control assembly according to the stack temperature. If the measured actual temperature of the stack deviates from the planned temperature, the deviation can be effectively corrected by using the rating or reference, thereby stabilizing the stack temperature.

[0026] There are various means of determining whether the aforementioned temperature detection sensor is functioning correctly. Among them, if the temperature detection sensor is damaged, the circuit may become open or short-circuited, and the temperature detected at this time is one of the two limit values ​​of the range, and it is possible to determine whether it is damaged or not based on this value. Furthermore, in order to improve the accuracy of the temperature sensor, verification can be performed using the following means. For example, a backup temperature sensor can be installed at the same time, and the difference between the two can be calculated. If the difference is within a predetermined range, it can be considered that the temperature sensor is functioning correctly. Alternatively, since the temperature acquisition cycle is fixed each time (the cycle for acquiring the temperature of the stack in real time by detection by the temperature sensor is 0.5 to 2 min, and in one embodiment, the acquisition cycle is 1 min), and the range of temperature change should be within a certain range, the change trend of the stack can be determined by the nearest 3 to 5 consecutive sampling temperatures, and it can be determined whether the detected temperature is opposite to the change trend, thereby determining whether the temperature detection sensor is functioning correctly.

[0027] Step 2: The current to the stack is acquired in real time, and it is determined whether the real-time current output by the stack is greater than a first predetermined current. If the real-time current output by the stack is greater than the first predetermined current, the rotation speed of the temperature control assembly is linearly adjusted to a predetermined duty cycle or less according to the magnitude of the current. If the real-time current output by the stack is not greater than the first predetermined current, Step 3 is performed.

[0028] Generally speaking, one of the main causes of heat generation in a stack is an abnormal output current; if the load on the stack is too large, the current output by the stack will increase accordingly. In order to predict the trend of changes in stack temperature early, in this embodiment, the heat generation status of the stack is predicted by detecting the real-time current output by the stack, and countermeasures are taken earlier to ensure that the fuel cell stack remains in the optimal temperature range.

[0029] Furthermore, when the real-time current output by the stack is greater than the first predetermined current, it is determined whether the stack real-time temperature is greater than the second predetermined temperature. If the stack real-time temperature is greater than the second predetermined temperature, the rotational speed of the temperature control assembly is linearly adjusted to a predetermined duty cycle or less according to the magnitude of the current. If the stack real-time temperature is not greater than the second predetermined temperature, the temperature control assembly is made to maintain its current rotational speed, and step 3 is executed. Once the temperature control assembly is adjusted to a specific rotational speed at the predetermined duty cycle, it is determined whether the stack real-time temperature is greater than the first predetermined temperature. If the stack real-time temperature is greater than the first predetermined temperature, the process returns to step 1. If the stack real-time temperature is not greater than the first predetermined temperature, the temperature control assembly is made to maintain its current rotational speed, and step 3 is executed.

[0030] Here, the second predetermined temperature must be lower than the first predetermined temperature, and the second predetermined temperature may be, but is not limited to, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, or 49°C. At this time, the temperature is between the first predetermined temperature and the second predetermined temperature, which is a relatively safe temperature, so temperature correction can be quickly achieved by linearly adjusting the duty cycle of the cooling assembly. Here, the predetermined duty cycle is related to the real-time current output by the stack, and generally, as the current increases, the predetermined duty cycle p also increases accordingly, and as the current decreases, the predetermined duty cycle p1 also decreases accordingly. In other words, a predetermined duty cycle p1 is linearly adjusted according to the magnitude of the current, and the rotational speed of the temperature control assembly is adjusted by adjusting the duty cycle (here, the duty cycle is the ratio of the time the load or circuit is on to the time the load or circuit is off. The duty cycle is sometimes called the "duty cycle" and is expressed as a percentage of the on time. A signal with a 60% duty cycle is on for 60% of the time and off for another 40% of the time).

[0031] Step 3: The voltage to the stack is acquired in real time, and it is determined whether the real-time voltage output by the stack is less than a first predetermined voltage. If the real-time voltage output by the stack is less than the first predetermined voltage, the exhaust valve is opened to exhaust air, and the temperature control assembly is blown for a predetermined time while maintaining the rotational speed at a predetermined duty cycle p1. If the real-time voltage output by the stack is not less than the first predetermined voltage, the temperature control assembly is adjusted to maintain the rotational speed at the initial duty cycle p2.

[0032] The exhaust policy of an air-cooled stack affects the stack's operating performance and hydrogen gas utilization rate. If the exhaust time is too short or the exhaust interval is too long, the stack may run out of fuel, potentially causing polarity reversal in the battery, as well as abnormally high temperatures, which could lead to stack ignition. Conversely, if the exhaust time is too long or the exhaust interval is too short, a large amount of unreacted hydrogen gas is released outside the stack, reducing hydrogen gas utilization and worsening the economic effectiveness of hydrogen gas. The stack is where the electrochemical reaction occurs and is the core part of the fuel cell power system, composed of multiple single cells stacked in series. In this embodiment, by acquiring the voltage of the stack, it becomes possible to reflect the basic status of multiple single cells as a whole. When the real-time current output by the stack is less than a first predetermined voltage, there is a possibility that polarity reversal is present or likely to occur. By detecting polarity reversal in some single cells in a timely manner, it is possible to ensure that the fuel cell stack is in the optimal temperature range.

[0033] Therefore, after opening the exhaust valve to exhaust air and blowing for a predetermined time while maintaining the rotational speed of the temperature control assembly at a predetermined duty cycle p1, it is further determined whether the real-time voltage output by the stack is less than a first predetermined voltage. If the real-time voltage output by the stack is less than the first predetermined voltage, the exhaust policy is adjusted to shorten the exhaust interval. If the real-time voltage output by the stack is not less than the first predetermined voltage, the temperature control assembly is adjusted to maintain the rotational speed at the initial duty cycle p2. By adjusting the exhaust policy, the single-cell polarity reversal phenomenon is avoided.

[0034] Compared to obtaining the voltage of the entire hydrogen fuel cell stack, the voltage of a single cell can be obtained continuously in real time to more accurately determine whether or not a polarity reversal has occurred. After opening the exhaust valve to exhaust and blowing for a predetermined time while maintaining the rotation speed of the temperature control assembly at a predetermined duty cycle p1, if the real-time current output by the stack is still less than the first predetermined voltage, the real-time voltage of a single cell is obtained, and it is determined whether the voltage of each single cell is within a second predetermined voltage range. If the voltage of each single cell is within the second predetermined voltage range, the rotation speed of the temperature control assembly is maintained at the initial duty cycle p2, and the stack is operating normally. If the voltage of each single cell is not within the second predetermined voltage range, the exhaust policy of the temperature control assembly is adjusted and the exhaust interval of the exhaust valve is shortened until the stack also operates normally while the temperature control assembly maintains the rotation speed of the initial duty cycle p2. If it is determined that the voltage of a single cell is negative, the stack can automatically repair itself and eliminate the fault by adjusting the exhaust policy of the temperature control assembly and shortening the exhaust interval of the exhaust valve. (Example 2)

[0035] Based on an inventive concept similar to the stack temperature control method in Example 1 described above, the present application further provides a fuel cell stack control system, which, as shown in Figure 2, comprises at least one data acquisition unit and at least one control unit.

[0036] Here, the data acquisition unit comprises a temperature detection unit electrically connected to the control unit and feeding back the real-time temperature of the stack to the control unit, a current detection unit electrically connected to the control unit and feeding back the real-time current of the stack to the control unit, and a voltage detection unit electrically connected to the control unit and feeding back the real-time voltage of the stack to the control unit.

[0037] The control unit analyzes the real-time data from the data acquisition unit by comparing it with a first predetermined temperature, a first predetermined current, and a first predetermined voltage, and adjusts the rotation speed of the temperature control assembly based on the data analysis results.

[0038] Furthermore, the control system A pressure sensor is provided to detect the pressure range of hydrogen gas introduced into the stack, and if the pressure is higher or lower than a predetermined value, it closes the intake valve of the stack to protect the stack and prevent the membrane electrode from being punched through. A temperature sensor is provided to detect the temperature inside the stack, and if the temperature is higher or lower than a predetermined value, it will turn off the stack to protect it and prevent irreversible damage to the stack. An intake valve installed in the hydrogen supply pipeline of the stack controls the amount of hydrogen gas supplied to the stack and the frequency of discharge, The system further includes an exhaust valve located at the exhaust port of the stack, which controls the amount and frequency of exhaust gas discharged after the reaction in the stack.

[0039] In one embodiment, the control system includes a first decision module that determines whether the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is greater than a first predetermined temperature, it adjusts the rotation speed of the temperature control assembly to maintain the stack temperature below the first predetermined temperature, and if the stack real-time temperature is not greater than a first predetermined temperature, it executes a second decision module; and a second decision module that determines whether the real-time current output by the stack is greater than a first predetermined current, and if the real-time current output by the stack is greater than a first predetermined current, it controls the load according to the magnitude of the current, with a predetermined duty cycle p1 or less The system further includes: a second decision module that linearly adjusts the rotational speed of the temperature control assembly below and executes a third decision module if the real-time current output by the stack is not greater than a first predetermined current; and a third decision module that determines whether the real-time voltage output by the stack is less than a first predetermined voltage, and if the real-time voltage output by the stack is less than a first predetermined voltage, opens the exhaust valve to exhaust air, blows the temperature control assembly for a predetermined time while maintaining the rotational speed at a predetermined duty cycle p1, and if the real-time voltage output by the stack is not less than a first predetermined voltage, adjusts the temperature control assembly to maintain the rotational speed at the initial duty cycle.

[0040] In one embodiment, the control system further comprises a first voltage detection mechanism provided for detecting the output voltage of the entire stack, and a plurality of second voltage detection mechanisms provided for detecting the real-time voltage of a plurality of single cells, wherein the first voltage detection mechanism and the second voltage detection mechanisms are electrically connected to the control unit, and the real-time voltage of the stack and the single cell voltage are fed back to the control unit.

[0041] In one embodiment, the control system further includes a fourth decision module that determines whether the temperature detection sensor is operating normally if the stack real-time temperature is greater than a first predetermined temperature, and if the temperature detection sensor is operating normally, adjusts the rotation speed of the temperature control assembly with PID, and if the temperature detection sensor is not operating normally, causes the temperature control assembly to maintain its current rotation speed and executes step 3.

[0042] In one embodiment, the control system includes a fifth determination module that determines whether the real-time temperature of the stack is greater than a second predetermined temperature when the real-time current output by the stack is greater than a first predetermined current, If the stack real-time temperature is greater than a second predetermined temperature, the rotation speed of the temperature control assembly is linearly adjusted to be less than or equal to a predetermined duty cycle p1, depending on the magnitude of the current. If the stack real-time temperature is not greater than a second predetermined temperature, the temperature control assembly maintains the current rotational speed and performs step 3, and when the temperature control assembly is adjusted to a specific rotational speed at the predetermined duty cycle p1, the fifth determination module further determines whether the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is greater than a first predetermined temperature, the process returns to step 1. The system further includes a fifth decision module that, if the stack real-time temperature is not greater than a first predetermined temperature, causes the temperature control assembly to maintain the current rotation speed and performs step 3.

[0043] In one embodiment, the control system opens the exhaust valve to exhaust air, maintains the rotational speed of the temperature control assembly at a predetermined duty cycle p1, and then performs a blow-by for a predetermined time, and further includes a sixth determination module that determines whether the real-time voltage output by the stack is less than a first predetermined voltage. The system further includes a sixth decision module that adjusts the exhaust policy to shorten the exhaust interval if the real-time voltage output by the stack is less than a first predetermined voltage, and adjusts the temperature control assembly to maintain the rotational speed at the initial duty cycle if the real-time voltage output by the stack is not less than the first predetermined voltage.

[0044] In one embodiment, the control system opens the exhaust valve to exhaust air, and after blowing for a predetermined time while maintaining the rotational speed of the temperature control assembly at a predetermined duty cycle p1, if the real-time current output by the stack is also smaller than a first predetermined voltage, a seventh determination module acquires the real-time voltage of a single cell and determines whether the voltage of each single cell is within a second predetermined voltage range. The system further includes a seventh decision module that adjusts the exhaust policy of the temperature control assembly and shortens the exhaust interval of the exhaust valve until the stack operates normally, with the temperature control assembly maintaining the rotational speed of the temperature control assembly at the initial duty cycle p2 when the voltage of each individual cell is within a second predetermined voltage range, and the stack operates normally, while the temperature control assembly maintains the rotational speed of the initial duty cycle p2 when the voltage of each individual cell is outside the second predetermined voltage range.

[0045] Various variations and specific examples of the stack temperature control method in Embodiment 1 described above can similarly be applied to the fuel cell stack control system of this embodiment. Based on the detailed description of the stack temperature control method described above, those skilled in the art will be able to clearly understand how to implement the stack temperature control device in this embodiment. Therefore, in order to keep the specification concise, a detailed explanation is omitted here.

[0046] This invention achieves a cooling effect by adjusting the rotation speed of the temperature control assembly without affecting the normal operation of the stack, by timely determining changes in stack temperature, output current, and output voltage, thereby ensuring that the fuel cell stack is always used within the optimal temperature range.

[0047] According to the fuel cell stack temperature control method of the present invention, when the stack exceeds a predetermined value, it is not necessary to shut down the stack and then start the temperature control assembly to cool it down, nor is it necessary to perform an operation stop process on the fuel cell stack to eliminate the fault, and it can be operated continuously and normally.

Claims

1. Step 1 involves obtaining the temperature of the stack in real time by detection using a temperature sensor, determining whether the stack's real-time temperature is greater than a first predetermined temperature, adjusting the rotation speed of the temperature control assembly to maintain the stack temperature below the first predetermined temperature if the stack's real-time temperature is greater than the first predetermined temperature, and executing Step 2 if the stack's real-time temperature is not greater than the first predetermined temperature. Step 2 involves acquiring the current from the stack in real time, determining whether the real-time current output by the stack is greater than a first predetermined current, and if the real-time current output by the stack is greater than the first predetermined current, linearly adjusting the rotation speed of the temperature control assembly to a predetermined duty cycle or less according to the magnitude of the current, and if the real-time current output by the stack is not greater than the first predetermined current, then executing step 3. A method for controlling the temperature of a fuel cell stack, comprising: step 3: acquiring a voltage to the stack in real time; determining whether the real-time voltage output by the stack is less than a first predetermined voltage; if the real-time voltage output by the stack is less than the first predetermined voltage, opening the exhaust valve to exhaust air and blowing air for a predetermined time while maintaining the rotational speed of the temperature control assembly at a predetermined duty cycle; and if the real-time voltage output by the stack is not less than the first predetermined voltage, adjusting the temperature control assembly to maintain the rotational speed at the initial duty cycle.

2. Step 1 is, If the stack real-time temperature is greater than a first predetermined temperature, the further step is to determine whether the temperature detection sensor is functioning correctly. A method for controlling the temperature of a fuel cell stack according to claim 1, further comprising the steps of: adjusting the rotational speed of the temperature control assembly with a PID when the temperature sensor is functioning normally, and causing the temperature control assembly to maintain its current rotational speed when the temperature sensor is not functioning normally, and performing step 2.

3. Step 2 is, The steps include determining whether the real-time temperature of the stack is greater than a second predetermined temperature when the real-time current output by the stack is greater than a first predetermined current, If the stack real-time temperature is greater than the second predetermined temperature, the rotation speed of the temperature control assembly is linearly adjusted to a predetermined duty cycle or less according to the magnitude of the current; if the stack real-time temperature is not greater than the second predetermined temperature, the temperature control assembly is made to maintain its current rotation speed, and step 3 is performed. A method for controlling the temperature of a fuel cell stack according to claim 1, further comprising the steps of: adjusting the temperature control assembly to reach a specific rotational speed at a predetermined duty cycle, determining whether the stack real-time temperature is greater than a first predetermined temperature; if the stack real-time temperature is greater than the first predetermined temperature, returning to step 1; and if the stack real-time temperature is not greater than the first predetermined temperature, causing the temperature control assembly to maintain the current rotational speed and performing step 3.

4. Step 3 above is, The steps include opening the exhaust valve to release the exhaust, blowing the temperature control assembly for a predetermined time while maintaining its rotational speed at a predetermined duty cycle, and then determining whether the real-time voltage output by the stack is less than a first predetermined voltage. A method for controlling the temperature of a fuel cell stack according to claim 1, further comprising the steps of: adjusting the exhaust policy to shorten the exhaust interval if the real-time voltage output by the stack is less than a first predetermined voltage; and adjusting the temperature control assembly to maintain the rotational speed at the initial duty cycle if the real-time voltage output by the stack is not less than a first predetermined voltage.

5. Step 3 above is, After opening the exhaust valve to exhaust air and blowing the temperature control assembly for a predetermined time while maintaining the rotational speed at a predetermined duty cycle, if the real-time voltage output by the stack is still less than the first predetermined voltage, The steps include acquiring the real-time voltage of a single cell and determining whether the voltage of each single cell is within a second predetermined voltage range, A method for controlling the temperature of a fuel cell stack according to claim 4, comprising the steps of: when the voltage of each single cell is within a second predetermined voltage range, maintaining the rotational speed of the temperature control assembly at an initial duty cycle, thereby ensuring that the stack operates normally; and when the voltage of each single cell is outside the second predetermined voltage range, adjusting the exhaust policy of the temperature control assembly and shortening the exhaust interval of the exhaust valves until the stack also operates normally with the temperature control assembly maintaining its initial duty cycle rotational speed.

6. The fuel cell stack temperature control method according to claim 1, wherein the period for acquiring the temperature of the stack in real time by detection using the temperature sensor is 0.5 to 2 min.

7. The method for controlling the temperature of a fuel cell stack according to claim 1, wherein the temperature control assembly comprises a heat dissipation fan provided to cool the fuel cell stack.

8. It comprises at least one data acquisition unit and at least one control unit, The aforementioned data acquisition unit is A temperature detection unit is electrically connected to the control unit and provides real-time stack temperature feedback to the control unit. A current detection unit is electrically connected to the control unit and feeds back the real-time current of the stack to the control unit, The control unit is electrically connected to a voltage detection unit that feeds back the real-time voltage of the stack to the control unit, The control unit analyzes the real-time data from the data acquisition unit by comparing it with a first predetermined temperature, a first predetermined current, and a first predetermined voltage, and adjusts the rotation speed of the temperature control assembly based on the data analysis results. The control unit includes a first decision module that determines whether the stack real-time temperature is greater than a first predetermined temperature, and if the stack real-time temperature is greater than the first predetermined temperature, it adjusts the rotation speed of the temperature control assembly to maintain the stack temperature below the first predetermined temperature, and if the stack real-time temperature is not greater than the first predetermined temperature, it executes a second decision module. A second decision module that determines whether the real-time current output by the stack is greater than a first predetermined current, wherein if the real-time current output by the stack is greater than the first predetermined current, the second decision module linearly adjusts the rotation speed of the temperature control assembly to a predetermined duty cycle or less according to the magnitude of the current, and if the real-time current output by the stack is not greater than the first predetermined current, the second decision module executes the third decision module. A fuel cell stack control system comprising: a third determination module for determining whether the real-time voltage output by the stack is less than a first predetermined voltage; if the real-time voltage output by the stack is less than a first predetermined voltage, the third determination module opens the exhaust valve to exhaust fuel and blows the temperature control assembly for a predetermined time while maintaining the rotational speed of the temperature control assembly at a predetermined duty cycle; and if the real-time voltage output by the stack is not less than a first predetermined voltage, the third determination module adjusts the temperature control assembly to maintain the rotational speed at the initial duty cycle.

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